TURBELLARIAN GROUP 



3445 



for instance which has been found in hothouses in Europe, where it has 

 been doubtless introduced from the Tropics with exotic plants is a dull yellow- 

 ish color above, but is ornamented with two reddish-brown bands, extending 



STRUCTURE OF A DENDROCCEUAN (enlarged five times). ' 



on each side of the back, and meeting near the front and hinder end of the 

 body. Another planarian not infrequently introduced into the conservato- 

 ries of Europe belongs to the genus Bipalium, this species (B. kewense} having 

 been first obtained in the plant houses at Kew. It is a strik- & 



ing creature, measuring upward of a foot in length when f[\ 



fully extended, and having the gray color of its skin relieved - : '- - 8> 



by three dark longitudinal bands running along the back 

 from the head to the tail. It is exceedingly flexible and con- 

 tractile, looking sometimes short and stout, and at other 

 times long and narrow. The head is susceptible of many 

 changes of form, assuming the shape of a hammerhead or the 

 blade of a cheese cutter, and the next moment being tongue 

 shaped. The skin is richly supplied with glands, secreting 

 a sticky slime, by means of which the Bipalium is able to 

 ascend perpendicular surfaces, and to lower itself from a 

 high point by letting out a thread of the material. It is said 

 to feed upon earthworms, and to propagate by division; the SMOOTH POLYCEUS. 

 tail end breaking off and growing into a second individual . The animal ; c. The eyes, 

 by acquiring a head, proboscis, and intestine. Land 



planarians are abundant in the damp tropical forests of Ceylon, South America, and 

 Australia; and a rich population of allied forms frequents the sea. One of the most 



TWO-STRIPED GEODESMUS. 

 (Enlarged twice.) 



PLANARIAN WORM, Planaria gonocephala (enlarged). 



striking of these marine forms is the tufted planarian (Thysanozoum), represented 

 in the illustration on p. 3446. Here the back is covered with many rows of dark- 



